Internal combustion engine



April 18, 1944. K J. v. CARON 2,346,729

INTERNAL COMBUSTION ENGINE Filed Sept. 5, 1942' Patented Apr. 18, 1944 UNITED S'i'itl INTERNAL COMBUSTION ENGINE Joseph Victor Caron, Haverhill, Mass.

Application September 3, 1942, Serial No. 457,116

3 Claims.

This invention, While not restricted thereto, relates more particularly to air cooled internal com busti-on engines and has for an object to increase the emciency of engines particularly of this type. In such engines a current of air is passed across the engine for cooling purposes, either by the use of a fan, or in the case of vehicles, by the motion of the vehicle, or by both methods. It will be noted, however, that the back portion of the engine which is not contacted by a uni-directional air current is not eiiectively cooled and that baffles to deflect the air currents around this portion would be essential in order to derive substantial cooling effect from fins at this location.

In accordance with this invention, therefore, the back portion of the engine is cooled, not by the current of air within which the engine operates, but by the air or gas which passes to the fuel intake of the engine. By this means not only is the back portion of the engine cooled, but the fuel supply is preheated, both adding to the efficiency of the engine.

A further object of the invention is to provide for the cooling of the crank case, the crank shaft, and the crank case oil by this same air or gas in the fuel upply system.

Further objects and advantages will appear from a more complete description of certain embodiments of the invention, in which Figure 1 is a front elevation of a four-cylinder opposed L head air cooled engine embodying the invention, certain parts being omitted.

Figures 2 and 3 are detail sectional views on lines 22 and 3-3, respectively, of Figure 1.

Figure 4 is a detail sectional view on line 4- 3 of Figure 2.

There is shown a four-cylinder air cooled engine, the cylinders being arranged in blocks of two in opposed relation to each other. A crank case I common to both of the cylinder blocks is arranged between the two cylinder blocks 2. Each of these blocks includes two cylinders 3 and these blocks as shown are arranged in slightly staggered relation so that the connecting rods t from the pistons 5 of the cylinders on one side of the crank case I are out of line with the corresponding portions of the other cylinders, so that the connecting rods may engage in pairs with the same crank portions 6 of the crank shaft 1. This crank shaft 1 is journaled in end and intermediate bearings 8 and 9. Beside the cylinder bores for the two cylinder blocks, each is provided between these bores with a smaller bore or passage 53 which opens at the end of the cylinder block adjacent to the crank case, and ex- FFICE tends into an intake passage ill at the head end of each of the cylinder blocks, this passage communicating with suitable valve intake ports at the head ends of each of the two cylinders of the block. outwardly of each passage I0, which may comprise a chamber in the separate cylinder head i i, are a pair of exhaust chambers I2 which may be open to discharge in any suitable manner.

Along the back edge of each of the cylinder blocks, as shown best in Figure 3, is an integral hollow rib i5. By back of the cylinder block is meant that portion which is away from the direction from which a current of cooling air contacts with the block in the normal operation of the engine, such cooling current being derived as is well known, either from a fan (not shown) driven by the engine, or by the effect of motion of the engine itself through the air when it is employed to drive a vehicle, or by both such means. The cooling of the cylinder blocks where the substantially linear current of air is in contact therewith and sweeps thereacross comprises, as shown, air cooling fins it. These extend from one side of the rib l5 along the corresponding side of the cylinder block, around the front of this block, and back on the opposite side of the block to the other side of the rib I5. For the purpose of this invention they may be formed in any suitable or usual way, but preferably they are made of pre-formed, preferably sheet metal, elements, the inner edges of which may be cast into the block in the manufacture of the cylinder block itself, and preferably in the manner disclosed in my application for Patent Serial No. 455,985, filed August 25, 1942, for Method of making heat interchange apparatus.

As shown the hollow within the rib i5, which forms a passage I1, and the bore or passage [3 between the cylinders, form portions of the fuel supply system for the engine. As illustrated, air supply for the carburetor opens into the head end of the passage ll through a port l8 formed in the cylinder head. The other or inner end of the passage ll communicates with a passage l9 which partly surrounds the rear bearing 8 and leads outwardly through the crank case cover 20 to the air inlet of the carburetor 2! which is mounted outside of the engine for accessibility. The air mixed with the fuel, and now in the form of a combustible gas, passes back through the cover 20 and into a passage 22 partly surrounding the intermediate bearing 9, from which it is lead directly to the crank case en of the bore l3, through which it passes to the head end of the cylinder block and into the gas intake chamber it) as previously described, being drawn in by suction of the engine pistons. It will be noted that there are two cylinder blocks and that the air passes from both substantially half way around the rear crank shaft bearing 8 and to the carburetor, while from the carburetor, the fuel mix ture divides and passes in opposite directions substantially half way around the intermediate hearing 9 before reaching the gas passage I3 between the cylinders.

It will thus be seen that the air and gas mixture passes twice along the lengths of the cylinders, first back of the rear cylinder and then between the two cylinders of each block with a travel through the crank case between the two traverses of the cylinder block. During this passage of the air and gas mixture it is heated from the hot cylinders so that the fuel supplied to the cylinders is preheated, while, in turn, this preheating of the air and gas also cools the cylinder blocks and particularly at the rear of the block where the current of air passing b the engine blocks would be ineffective to act upon cooling fins. It will also be apparent that since the air and gas pass through passages in the crank case around certain of the crank shaft bearings, the crank case, these bearings and the cylinder oil will be cooled thereby, while at the same time these parts are giving up heat to the fuel and air.

From the foregoing description of certain embodiments of this invention it should be evident to those skilled in the art that various modifications and changes might be made and the invention might be embodied in engines of widely difiering design and cylinder arrangement without departing from the spirit or scope of this invention.

Iclaim:

1. An engine comprising a cylinder block having a plurality of cylinders in spaced parallel relation therein and an integral hollow rib along one end of said block, said block having a bore between adjacent cylinders of a pair, connections between the hollow of said rib and said bore, a carburetor in said connections, and a fuel intake system including said bore, carburetor, connections and the hollow of said rib, whereby the fuel acts to cool said engine and said engine acts to preheat the fuel.

2. A structure as specified in claim 1; said engine including crank shaft bearings; said connections including passages extending at least partially around said bearings to cool the same.

3. In an internal combustion engine, a crank case having crank shaft bearings; a block connected with said crank case and having cylinders; said crank case being provided with an air passage extending at least partially around one of said crank shaft bearings and with a mixture passage extending at least partially around another of said crank shaft bearings; said block being provided with an air passage and with a mixture passage, one of these passages extending longitudinally of and between adjacent cylinders and the other extending in the same direction at the back of said block; and a carburetor at the exterior of said crank case, said carbureter having an air inlet communicating with said air passage of said crank case and a mixture outlet communicating with said mixture passage of said crank case; said air passages of said crank case and block being in communication with each other and constituting heating and conducting means for the air flowing to said carbureter, said mixture passages of said crank case and block being in communication with each other and constituting heating and conducting means for the mixture flowing from said carbureter to said cylinders, the air and mixture flowing through said passages constituting cooling media for said block and said crank case bearings.

JOSEPH VICTOR GABON. 

